This proposal is for the Biostructure Core Facility of The Forsyth Institute to obtain a Leica TCS SP2 Confocal Laser Scanning head mounted on an upright DM RXE microscope (CLSM) with a series of water, air, and oil objectives, fired with Ar ion and two He/Ne lasers. A satellite image analysis center is included. Forsyth is the worlds foremost independent research institute in oral and craniofacial biology. In order to maintain high standards of achievement it is time to expand existing instrumentation. Several of the grantees currently outsource time on different CLSMs, two grants depend on CLSM use, and two have recent publications using CLSM. Obtaining a CLSM ideally enhances four broad scientific interests at Forsyth. (1) Several investigators at Forsyth are studying oral biofilm formation, the interaction of biofilm with epithelial cells, or the immune response to biofilm. The CLSM is the instrument of choice for the study of the bacterial composition of biofilm. (2) Others at Forsyth are studying specific gene expression, protein expression and molecular interactions in craniofacial mutations occurring in humans. The Zebrafish facility at Forsyth is a source of embryos used to study genes and proteins involved in normal and mutant craniofacial cartilage differentiation. The optical sectioning capability of the CLSM is ideal for locating fluoroprobes used to mark genes and proteins in cells and tissues. (3) Basic research is conducted at Forsyth in the interaction of cell adhesion molecules, the cytoskeleton, and enamel matrix proteins in biomineralization. (4) Another focal interest is exploring mechanisms of gene regulation in bone resorption by localizing gene expression, protein elaboration and molecular interactions in osteoclasts. The CLSM is designed to accommodate techniques that address these research approaches. Use of the CLSM will be shared among more than 12 investigators, their post-doctoral fellows, and scientists from Northeastern University and Harvard School of Dental Medicine. The Forsyth CLSM Oversight Committee will regulate all aspects of CLSM use. The Forsyth Institute guarantees to provide: 1) all necessary renovations for housing the CLSM, 2) the service contract for the life of the instrument, 3) applications support, and 4) a trained operator to be available for all users of the CLSM.